Process for produced stabilized olefin

ABSTRACT

A method is described whereby olefin terpolymers, consisting of ethylene, an alpha olefin and a polyene having in the molecule, in addition to the double bond participating in the formation of the macromolecule, at least one conjugated double bond system, are stabilied against oxidative aging without destroying their characteristic high vulcanization rate by reacting them with a dienophilic agent represented by one of the following formulae:   WHEREIN R and R6 may be an alkyl, alkenyl, cycloalkyl, aryl or aralkyl radical having up to 8 carbon atoms, R1, R2, R3, R4 and R5 may be hydrogen or alkyl, aryl, cycloalkyl or aralkyl radicals having up to 8 carbon atoms, the R1-R2 and R-R pairs may be divalent radicals forming condensed rings.

"United States Patent [191 Arrighetti et a1.

451 July 1, 1975 PROCESS FOR PRODUCED STABILIZED OLEFIN [75] Inventors:Sergio Arrighetti; Sebastiano Cesca; Giuseppe Ghetti; Eugenio Vajna, allof San Donato Milanese, Italy [73] Assignee: Snam Progetti S.p.A., SanDonato Milanese, Italy [22] Filed: July 28, 1972 [21] Appl. No.: 275,936

[30] Foreign Application Priority Data July 31, 1971 Italy 27014/71 [52]US. Cl. 260/66; 260/45! R; 260/457 S; 260/63 R; 260/807; 260/8078;260/878 R; 260/879 [51] Int. Cl. C08! 15/40; C08f 27/18 [58] Field ofSearch..... 260/66, 878 R, 879, 45.7 R, 260/63 R, 80.78, 80.7

[56] References Cited UNITED STATES PATENTS 3,538,193 11/1970 Meredith260/878 R 3,652,514 3/1972 Cesca et a1. 260/8078 3,657,204 4/1972 Cescaet al. 260/8078 3,764,588 10/1973 Arrighetti et a1. 260/807 PrimaryExaminerLucille M. Phynes 5 7 ABSTRACT 0 u R Ch C-C-R6,

R1, R2 a CH o-c c-o wherein R and R may be an alkyl, alkenyl,cycloalkyl, aryl or aralkyl radical having up to 8 carbon atoms, R R R Rand R may be hydrogen or alkyl, aryl, cycloalkyl or aralkyl radicalshaving up to 8 carbon atoms, the R -R and RR pairs may be divalentradicals forming condensed rings.

7 Claims, No Drawings PROCESS FOR PRODUCED STABILIZED OLEFIN enters inthe macromolecule formation, also at least a conjugated double bondsystem which is disposible for the subsequent vulcanization.

It is also known that said terpolymers present a very high vulcanizationrate, comparable with those of the diolefin polymers such as naturalrubber, polybutadiene, polyisoprene and the like.

This property can be advantageously utilized for the covulcanization ofsaid terpolymers when admixed with the above diene polymers orcopolymers. However it is to be noted that some of these terpolymerspresent, when unvulcanized, a tendency to ageing caused by the presenceof the very reactive conjugated double bond systems.

We have found that the above terpolymers can be stabilized againstoxidative ageing without losing their characteristic high vulcanizationrate.

The first object of the invention is a process for stabilizingterpolymers by reacting them with dienophilic agents.

A second object of the present invention is to provide stabilizedterpolymers obtained from that process.

Another object of the present invention is to provide vulcanizedterpolymers obtained from those stabilized terpolymers.

The employed olefin terpolymer includes along the polymer chain one ofthe following groups:

wherein R and R are substituents different each other. one of them beingalways hydrogen the other being an alkadienyl radical of the kind CR'CR" CR" I C and RI RI rl c=c CR"'- C R! RIII or an alkenyl radical as:

RI II I l C C RH! RI R" RHIQR" RVQRIV un 2 wherein the double bond isconjugated with-a double bond present in the ring, R being always analkyl radical and R. R" and R can be hydrogen or alkyl and aryl radical;moreover the radical may be of the general formula:

n being comprised between 0 and 5, B being a cyclodienic radicalselected among wherein R, R, R' and R" have the abovementioned meanings.Furthermore the employed olefin polymers are the ones containing in thepolymeric chain one of the following groups III wherein R, R, R and R"can be hydrogen, alkyl or aryl radicals, alone or by pair can bedivalent radicals able to form a condensed ring.

Illustrative examples of olefin polymers advantageously employableaccording to the invention are the terpolymers disclosed and claimed bythe applicant in the Italian Pat. No. 843,706 and 851,691 correspondingto US. Pat. Nos. 3,652,514 and 3 ,657,204, respectively, and in theItalian applications for patent n 19653/A/ and 19657 A/7O correspondingto US. Pat. No. 3,764,588 and US. Application Ser. No. 108,974, nowabandoned, respectively, and others based on the following termonomers:

3 I 01 f? or (Z-norbon 5 enyl) -l' or 2' or 3' methyl-l or 2' or 5cyclopentadienyl) methane Dehydro-iso-dieyclopentadiene r H CH 2-(2,4"-dimethyl-penta l, 3' dienyl-) -norborn S-ene2,3-dimethylen-norborn--ene The reaction time depends on the reactivityof the dienophilic agent and on the employed temperature, however it maybe from some minutes to 50 hours.

Said stabilized terpolymers can be employed in the A 5 field of thesynthetic rubbers, either for particular purg l b -g 5. i poses oradmixed with other synthetic rubbers with The dienophilic reagentsemployable in the process Which it can be Vulcanizedaccording to thepresent invention are the ones which h following illustrative cxdmplesillustrate the have one of the following general formulae: Venue:

O m EXAMPLE 1 150g of a terpolymer containing ethylene (60% by R C N a Ca S weight), propylene (39.5% by weight) and methyl- 0 cyclopentadienylnorbornenyl methane (0.5% by weight), prepared according to the Italianpatent R R 851,691 and having [1;] 2.l dl/g in toluene at 30C, weredissolved into 5 liters of toluene whereto 3g of methyl-vinyl ketonewere added. The solution was 21 2 stirred at room temperature for 8hours, whereafter the polymer was coagulated with an excess of methanol,dissolved in n-hexane, coagulated again with methanol, dried undervacuum at 50C. The polymer was still soluble and its intrinsic viscosityin toluene at 30C was H CH 22 dl/g.

25 On the obtained product tests of resistance to ther- 0 C C 0 malageing have been carried out in a oven provided with a forcedcirculation of air, at 100C, and tests of N vulcanization have beencarried out at 145C. On table I 1 data are reported concerning theageing tests, carried R out on the original polymers and on the modifiedpoly- 5 mer according to present example.

On table 2 the variations of Mooney viscosity have been reporteddepending on the ageing times com pared with the ones of the originalpolymer which have R5 CH CH S02 R been assumed to be 100.

With the polymer subjected to the treatment indicated in the presentexample a mix has been prepared according to the following recipe:polymer 100, HAF R5 CH C "C R6 50, ZnO 5, cyclohexyl benzothiazylsulphenamide l, sul hur 1.7 which has been cured at 145C for 60minwherem R and b alkyl alkenyl cycloalkyl my] utez. The tensile stresstests on vulcanized specimens or arylalkyl radical having up to 8 carbonatoms, R R gave the results reported on table 2. R5 be Q or alkyl arylCycloalkyl or The treatment carried out on the terpolymer gave lalkylradlczfls havmg up to 8 Carbon atoms f therefore asubstantialimprovement ofthe ageing resismore the pmrs and 1 l f may form dwalenttance thereof allowing on the other side its effective hydrocarbonradicals which give rise to condensated vulcanization rings.

Illustrative examples of dienophilic agents employed EXAMPLE in thepresent invention are: Terpolymers containing ethylene, propylene andthe acetyl* acrylaryl' and benzoyl'isothlocyanatemalel 5O termonomerindicated in table 1 were dissolved in tolumlde, y y ethyl Vinyl ketohe,methyl ene, reacted with various compounds having dieno- Vinyl Sulphomand the like- Said dienophilic agents philic character indicated ontable 1 and purified ac- IEZICI very easily with terpolymers under mildcondie rding to the procedures of example I IiOflS at 8 temperatureComprised between and The ageing and vulcanization tests were carriedout 150C Preferably between 150 and advflfltaas is example 1, theresults are reported on table 2. in geously but not restrictively thereaction takes place in all cases an improvement was observed as to theageing hydrocarbon solutions of the olefin polymer the conresistance incomparison with non modified polymers centration of the latter beingcomprised between 0.1 owing to the reaction with dienophilic agenttogether and 20%. with a good vulcanization of modified polymers.

TABLE 1 Dienophilic (1;) ml. Example (1 )I0l. Ethylene Propylene Termo-Termo- Dienophilic agent sole (3) 30C (after nomer nomer 30C (71 by (7:by (/1 by type 1) agent type (2) Tcrmonomcr sole treatment) weight)weight) weight) I ll 39,5 0.5 A MVK 10,6 2,2 2 1.8 58 39,9 2.] A NO 121,9 3 1.60 55 42,2 2,5 A TBO 3 1,7

TABLE 1 -Continued Dienophilic (1;) to]. Example (1 tol. EthylenePropylene Termo- Termo- Dienophilic agent sole (3) 30C (after nomernomcr 30C (7( by ('71 by ("/1 by type (I) agent type (2) Termonomcr soletreatment) weight) weight) weight) 4 1.5 60 48.2 L8 A MA 5 1.6 5 1.75 6147.l 1.9 A MVS 5.5 1.4 6 2.00 56 42.2 1.8 B MA 2.2 L8 7 L65 54 43.5 2.5C M80 5 1.9 8 1.70 57 40,7 2.3 C ASC 1.8 9 1.90 58 38.5 3.5 D MVK 11.22.] 10 2.20 55 42.2 2.8 E NO 3.5 2.35

I l A (2 norbor-S enyl) l or 2' or 3 methyl l or 4' or 5'cyclopentadienyl) methane B lZ-norhonS-cnyl) l or Z or 3'cyclupentadienyl) methane tlehydro-isodicyclopentadicne I) 2(2. 4'dimerhylpenta -l 3 dientyl) norhor-S ene l? (Z-norbor-S enyl) (3'. 5'.5' trimethyl cycluhexwl 3 dienyl) methane (2) NO naphthnquione TBO rurtbut \l quinone MA maleanil MVS methylrinyl sulphone MBO methylhenzuquinonc ASC ucroylsulphucyanide M\'l\' methyl-vinylketunc (3)reacted at room temperature Table 2 Example Mooney modified polymer MTensile Elongation Mooney original polymer loo strength at break Tension26 hours 42 hours 300 hours (Kg/cm'-') (Kg/cm) (/1) set l 21 45 24 163665 50 2 I l 7 60 234 490 I7 3 8 26 79 245 445 8 4 7 9 64 18 1 10 790 605 28 36 43 2 l 129 705 50 6 23 50 200 440 50 7 15 2O 35 60 240 450 50 818 26 50 45 250 420 15 9 25 3O 4O 60 220 420 l0 l0 1 l 2 60 240 440 l5What we claim is:

1. A process for preparing an olefin terpolymer which is stabilizedagainst oxidative ageing, which comprises reacting in a hydrocarbonsolvent and at a temperature between 0 and 150C.

a. a terpolymer of ethylene, another alpha olefin, and 4 a polyene whichis a methyl-cyclopentadienyl norbornenyl methane having in addition to adouble bond for participating in the terpolymer formation, conjugateddouble bonds in the cyclopentadienyl substituent, with b. a dienophilicagent of the general formula:

R5 ca: 0 0 -R6 wherein R can be hydrogen or alkyl, aryl, cycloalkyl orarylalkyl radicals having up to 8 carbon atoms and R can be an alkyl,alkenyl. cycloalkyl, aryl or arylalkyl radical having up to 8 carbonatoms.

2. The process according to claim 1 wherein said dienophilic agent ismethyl-vinyl ketone.

ii. redissolving the polymer in a solvent therefor;

iii. contacting the product and solvent mixture again in an excess ofmethanol to coagulate the polymer and separate the polymer; and

iv. drying the polymer.

6. The polymer product obtained according to the process of claim 5.

7. Terpolymers stabilized against oxidative ageing consisting of thereaction product prepared according to the process of claim 1.

1. A PROCESS FOR PREPARING AN OLEFIN TERPOLYMER WHICH IS STABILIZEDAGAINST OXIDATIVE AGEING, WHICH COMPRISES REACTING IN A HYDROCARBONSOLVENT AND AT A TEMPERATURE BETWEEN 0* AND 150*C. A. A TERPOLYMER OFETHYLENE, ANOTHER ALPHA OLEFIN, AND A POLYENE WHICH IS AMETHYL-CYCLOPENRADIENYL NORBORNENY METHANE HAVING IN ADDITION TO ADOUBLE BOND FOR PARTICIPATING IN THE TERPOLYMER FORMATION, CONJUGATEDDOUBLE BONDS IN THE CYCLOPENTADIENYL SUBSTITUENT, WITH B. A DIENOPHILICAGENT OF THE GENERAL FORMULA:
 2. The process according to claim 1wherein said dienophilic agent is methyl-vinyl ketone.
 3. The processaccording to claim 1 wherein the hydrocarbon solvent is toluene.
 4. Theprocess according to claim 1 wherein the reaction occurs at atemperature in the range from 15*-90*C.
 5. The process of claim 1including recovering the stabilized olefin terpolymer reaction productfrom the hydrocarbon solvent by the steps comprising i. contacting theproduct and solvent mixture with an excess of methanol to coagulate thepolymer and separate the polymer; ii. redissolving the polymer in asolvent therefor; iii. contacting the product and solvent mixture againin an excess of methanol to coagulate the polymer and separate thepolymer; and iv. drying the polymer.
 6. The polymer product obtainedaccording to the process of claim
 5. 7. Terpolymers stabilized againstoxidative ageing consisting of the reaction product prepared accordingto the process of claim